Demographic, Clinical, and Immunologic Correlates among a Cohort of 50 Cocaine Users Demonstrating Antineutrophil Cytoplasmic Antibodies

OBJECTIVE

Cocaine/levamisole-associated autoimmunity syndrome (CLAAS) is a poorly understood form of drug-induced autoimmunity. Our goals were to better characterize the spectrum of clinical and immunologic features of CLAAS, to identify demographic risk factors, and to generate new hypotheses regarding pathogenesis.

METHODS

CLAAS subjects were identified between 2001 and 2015 at the University of Washington Medical Center, Harborview Medical Center, and affiliated clinics in Seattle, Washington, USA. Demographic, clinical, and immunologic variables were collected and correlated using contingency and logistic regression analyses. We used similar analyses to compare CLAAS subjects with all individuals exhibiting antineutrophil cytoplasmic antibodies (ANCA+) or cocaine use (Cocaine+) in an associated deidentified clinical data repository.

RESULTS

We identified 50 CLAAS subjects. Compared to all Cocaine+ individuals (n = 2740), CLAAS subjects were more likely to be female and less likely to self-identify as black/African American. CLAAS subjects showed several ANCA patterns, including anti-MPO (myeloperoxidase)/anti-PR3 (proteinase 3) dual reactivity, a finding that appears to be specific to CLAAS. Hematologic, renal, and skin abnormalities were most frequently reported, including neutropenia and skin purpura. Finally, we observed strong, independent associations between the cytoplasmic ANCA (C-ANCA) pattern and mortality.

CONCLUSION

We identify sex and race as important risk modifiers in the developing CLAAS among cocaine users. The development of C-ANCA was associated with increased mortality. Moreover, we confirm the enriched presence of anti-MPO/anti-PR3 dual reactivity in CLAAS, further supporting the diagnostic utility of this feature.

Closing the Serological Gap in the Antiphospholipid Syndrome: The Value of "Non-criteria" Antiphospholipid Antibodies

OBJECTIVE

Most clinicians use the 2006 Sydney classification criteria to evaluate patients suspected of having antiphospholipid syndrome (APS). Although sensitive and specific for APS, many patients fulfilling clinical criteria for the syndrome are persistently negative for the specific serological tests ("laboratory criteria"). These "seronegative APS" (SN-APS) patients can go undiagnosed and untreated until they experience serious clinical events. This study's objective was to describe antibody profiles of SN-APS patients using non-criteria markers, assess the clinical utility of these markers separately and in combination, and suggest incorporation into guidelines for patients suspected of APS.

METHODS

We categorized 175 consecutive patients suspected of APS into 2 subgroups: 107 fulfilling Sydney APS classification for seropositive APS (SP-APS) and 68 with clinical manifestations suggestive of APS but having negative serology, on 2 occasions, for criteria markers (SN-APS). On study inclusion, samples were retested for criteria and 11 non-criteria markers, including antiphosphatidylserine/prothrombin antibodies.

RESULTS

Using 4 of 11 non-criteria tests, a cumulative 30.9% of SN-APS patients were detected. Combining results of all 11 non-criteria tests, 25 SN-APS (36.8%) and 89 SP-APS (83.2%) were positive for 1 or more non-criteria antibodies.

CONCLUSION

Failure to diagnose APS can result in severe clinical consequences. Patients displaying clinical features of APS, but negative for conventional criteria markers, should undergo additional testing for non-criteria biomarkers. In our cohort, around one-third of SN-APS patients showed reactivity to 1 or more non-criteria markers. An update to the current classification criteria incorporating new serological markers should be considered to identify and stratify patients with APS for more effective treatment and management.

Factor H Autoantibodies in Patients with Antiphospholipid Syndrome and Thrombosis

OBJECTIVE

Autoantibodies to complement factor H (FH) are associated with atypical hemolytic uremic syndrome, but can also be detected in patients with rheumatoid arthritis and in patients positive for lupus anticoagulants and thus potentially antiphospholipid syndrome (APS). To our knowledge, no data are available on the association between the presence of FH autoantibodies in APS and clinical manifestations.

METHODS

We determined FH autoantibody levels using ELISA in 2 cohorts of patients with primary (PAPS) and secondary APS (SAPS) from Serbia and Italy, and an additional cohort including patients with venous thromboembolism (VTE) from Sweden.

RESULTS

FH autoantibodies were detected in 13.7% of patients (n = 73) with PAPS and 30.3% of patients (n = 33) with SAPS in the Serbian cohort. FH autoantibody frequency in the Italian cohort was 33.3% (n = 15) and 36% (n = 25) in PAPS and SAPS, respectively. Both FH autoantibody levels and frequencies observed in both APS cohorts were significantly higher than in matched healthy controls (5%). Further, patients with PAPS with venous thrombosis in the Serbian cohort had significantly higher levels of FH autoantibodies. Therefore, we analyzed a dedicated Swedish thrombosis cohort and found that patients with FH autoantibody positivity had higher risk of VTE recurrence (HR 2.0, 95% CI 1.2-3.3, p = 0.011) compared with the reference group of FH autoantibody-negative patients.

CONCLUSION

Overall, the data indicate that in patients with APS and recurrent venous thrombosis, there are increased levels of FH autoantibodies, a finding associated with poor clinical outcome.

Prevalence and significance of persistently positive antiphospholipid antibodies in women with preeclampsia

OBJECTIVE

To determine the prevalence of antiphospholipid antibodies (aPL) and their association with obstetric outcomes in women with preeclampsia.

METHODS

The study included 150 patients. Clinical variables, risk factors, and severity criteria for preeclampsia and aPL were analyzed.

RESULTS

We found aPL in 4% of patients without risk factors for preeclampsia and in no women with risk factors (p = 0.03). Fifty percent of aPL-positive patients had a fetus with intrauterine growth restriction versus 13.9% (p = 0.04). No relation between aPL and severe preeclampsia was found.

CONCLUSION

The prevalence of aPL among women with preeclampsia is low. aPL can predispose women without risk factors to preeclampsia.